Lighting bollards have been used broadly in numerous urban, industrial, landscaping and architectural applications. Lighting bollards must be designed to withstand harsh environments, vandalism and they must endure significant day to day abuse over extended periods of times. Many times lighting bollards are designed to be used as barricades for preventing vehicle access. It is common for vehicles to graze or impact the bollard. As such, it is necessary to maintain strength of the bollard while maintaining the aesthetic standards of the surrounding environment.
Manufacturers have used various materials and construction designs to strengthen or harden the bollard and maximize their useful and aesthetic life. Solid, extruded or cast metals and formed concrete with rebar reinforcement and a hollowed axial core have been used. These types of bollards proved to have strength; however, such construction is expensive and if replacement is required because of external impact damage or aesthetic deterioration the expense is exacerbated. Additionally, to mount such bollards requires heavy duty base supports or integration of bollard into the construction of the base platform. This is often times inconvenient and expensive.
Accommodation of lighting components tended to further weaken the bollards or create limitations with the replacement of lighting fixtures. To reduce cost and to better accommodate lighting applications, bollard designs migrated to the use of heavy gauge steel tubing welded to a bottom mounting plate and capped by a permanent lighting fixture. U.S. Pat. Nos. 4,999,749 and 5,075,833 issued to Dormand discloses such a design. One limitation with this type of design is that the upright strength is dependent on the integrity of the tubing structure. If there is any dent in the upright tube caused by an impact the overall strength of the tube is significantly diminished. Additionally, for a bollard that has suffered impact damage to the exterior surface, the entire bollard would still need to be replaced to maintain overall aesthetic appeal in the environment.
Dorman also integrates the lighting fixture into the upright tube and includes louvers welded to outer surface of the tube to disperse light. This is a further disadvantage because it does not allow for easy replacement of the light fixture, which is highly desirable in many applications. It also limits the type of light that can be used because once installed it is prohibitive to replace the type of light originally installed. A number of attempts have been made to overcome these limitations with only partial success. U.S. Pat. No. 6,402,337 issued to LeVasseur et al. discloses a bollard light having an adjustable light distribution pattern. The light distribution pattern is modified by adjustment of a cap assembly that increasingly covers a portion of the light fixture assembly to redirect the light. In order to ease in the replacement of the internal light fixture, LeVasseur discloses an internal frame structure to support the lighting fixture. An external sleeve that is connected to a mounting base by screws and constituting the major body of the bollard covers the internal frame structure, and it can be interchanged with sleeves of different heights. Although it is desirable to have the ability to interchange the outer bollard cover to maintain aesthetic appearance, because of this structure, there is innate weakness in the overall structure of the bollard. Therefore a need exists for a lighted bollard system that provides solutions to the aforementioned deficiencies in the prior art. In view of the foregoing background, the present invention overcomes the limitations of the prior art.